Actually, backers who donated that amount of money, their names are in the monastery in the game, take a look.
Digital Rewards
We plan to release all digital rewards with the release of Kingdom Come: Deliverance. We plan to add a Steam login to your profile, so we can add the rewards like game, soundtrack and artbook via Steam directly. Other digital bonuses will be delivered via direct link in your profile. In any case, the instructions for downloading the digital rewards will be stored in your profile even after release of the game.
In-game rewards for high tier backers, such as an in-game name, picture or statue were already implemented in the game. Can you find yourself in the game?